For the illustration of symbols in grid form, among others, straight-line dot grids (row dot grids) and surface-dot grids (area-dot grids) are known.
In the case of straight-line dot grids, each symbol is composed of individual rows of grid dots applied one row after the other, by means of selectable punching pins attached from one single row of punching pins.
In the case of the surface-dot grid for punching of a symbol, there must be provided a set of punching pins which covers the entire symbol and from which the punching pins necessary to form the symbol are selected (compare German OS No. 22 23 305=U.S. Pat. No. 3,770,093).
Conventional punching apparatuses are known only for symbols of one size of lettering or one type of lettering. A selection of the size of lettering or of the type of lettering would, if at all, only be possible if the entire punching tool would be exchanged.
The basic purpose of the invention is to give a punching apparatus, the construction of which is simplified and can be changed with the lettering and punching size without effort.